This invention relates generally to seating systems and is particularly concerned with a seating system, especially useful for automotive vehicles, in which a seat is provided with one or more bolsters.
Bolsters are often utilized in seating systems to provide additional support for an occupant. Typically, bolsters are disposed on laterally opposite sides of the seat cushion to provide lateral support for an occupant, such as along hips and thighs.
In previous bolster designs, mechanical hinges have been used to mount bolsters on seat cushions to facilitate the effectiveness of the bolsters in providing lateral support. In other words when an occupant seats him or herself on the seat cushion, the weight of the occupant depresses the cushion, and the hinging action, or articulation, of the bolsters provides for the bolsters to be operated to laterally engage the hips and thighs of the seated occupant. In a motor vehicle where an occupant is subject to side forces when the vehicle turns, bolster-equipped seats provide extra seating comfort and stability.
Prior designs of this nature have had the bolsters as separate parts of the seat assembly. The bolsters are foamed and trimmed as individual units and then later assembled to the seat cushion. This type of design requires foam-free surfaces to allow hinging of the bolster units. Because additional assembly operations are required, additional manufacturing expenses are incurred.
The present invention is directed to a novel and unique construction for adjustable bolsters which utilizes an encapsulation concept wherein the mechanism which provides for the pivotal action of a bolster on a seat cushion is achieved by the integral formation of the bolster with the seat cushion. Stated another way, a body portion of the bolster is integrally foamed with a body portion of the seat cushion, and a joining portion of the foam, typically of reduced thickness, integrally joins the two body portions to provide a line of hinging via which the bolster can pivot with respect to the seat cushion. One result of the invention is that a more cost-effective construction results because there are less trimming and assembly operations required.
In order to provide enhanced durability for certain designs it is desirable to incorporate additional hinging structure within the foam material. Several forms of such hinging structure are contemplated and will be described in detail hereinafter. Such hinging structure is preferably fully encapsulated within the foam material. Benefits of such encapsulation include noise insulation. Less expensive material for the hinging structure can be used because it is not an appearance item.
The invention also provides for a new and unique way to trim a seat cushion and bolster wherein the seat covering material extends laterally from the seat cushion, over the joining portion which forms the hinge axis, and over upwardly and laterally outwardly facing surfaces of the bolster, and is finally trimmed off adjacent a lower edge portion of the bolster. This provides a wrinkle-free and non-stretch construction whereby wrinkling and stretching of the cover are substantially eliminated for bolster operation over its range of possible adjustment positions.
The construction is also advantageous in that the foam material has a certain return memory so that the as-foamed position defines the relative position which a bolster will inherently tend to assume with respect to a seat cushion. Yet the construction provides for ready adjustment of the bolster to and from this return position.
The invention also offers the opportunity for cooperative association of different mechanisms with a bolster. The present application discloses a completely passive bolster system. In other words the as-foamed position and the seat assembly's structural characteristics will determine the positions which the bolster assumes as a function of the physical characteristics of occupants. If necessary, additional means, springs for example, can be incorporated to coact with the bolsters. A bolster can also be adapted to a passive mechanical system in which it is passively adjusted by the occupant's body pressure but can be held in a desired position by a mechanical device.
Still further, the principles of the invention are well adapted to lightweight sturdy seat constructions by the particular relationship of the bolster and hinging mechanism in relation to an underlying base structure for the seat. Not only do functional improvements in this context accrue from the invention, but the construction also presents a pleasant finished appearance because the finishing of edges and the like may take place in concealed areas which are not exposed to view in normal use of the seat.
The foregoing features, advantages, and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.